Haem Flashcards
(75 cards)
What does the bone marrow do?
Produces blood cells (red cells, white cells, and platelets).
Manages red cell disorders, white cell disorders, platelet disorders, clotting, and transfusion.
What are the types of white blood cells?
Neutrophils
Eosinophils
Basophils
Monocytes
Lymphocytes
What are the common causes of anaemia?
Loss: Bleeding
Destruction
Reduced production
Diagnosis involves history, examination, and tests like blood film, automated counts, MCV, and Hct.
How is anaemia classified by MCV (Mean Corpuscular Volume)?
Normocytic:* Anaemia of chronic disease, Mixed picture*
Microcyti**c:* Chronic blood loss, iron deficiency, thalassaemia, spherocytosis*
Macrocy**tic:* B12/F*olate deficiency, thyroid issues, alcohol, reticulocytes (immature cells).
What are the mechanisms of anaemia due to destruction?
Intravascular: Schistocytes, toxic damage, complement, mechanical causes.
Haptoglobin overwhelmed, iron accumulation.
Extravascular: Red cells are consumed by macrophages in the liver/spleen.
Bound immunoglobulins or physical issues like spherocytes.
What are the tests used to diagnose anaemia?
Blood film
Automated counts
Mean Corpuscular Volume (MCV)
Haematocrit (Hct)
What are the key features of microcytic anaemia?
Chronic blood loss leading to iron deficiency.
Thalassaemia, sickle cell disease.
Spherocytosis.
What are the key features of macrocytic anaemia?
B12 or folate deficiency.
Thyroid issues.
Alcohol-related liver disease.
Presence of reticulocytes (immature red cells).
How do white cells function in the immune system?
Neutrophils: Fight bacterial infections.
Eosinophils: Combat parasites and allergens.
Basophils: Release histamine in allergic reactions.
Monocytes: Phagocytosis and antigen presentation.
Lymphocytes: Include T cells, B cells, and natural killer cells for adaptive immunity.
What are the main components of clotting?
Platelets
Coagulation factors
Fibrinogen
Endothelial cells
What are red blood cells responsible for?
Transporting oxygen via haemoglobin.
Removing carbon dioxide from the body.
What is the lifespan of a red blood cell?
Approximately 120 days.
How is haemoglobin structured?
Composed of four protein subunits (two alpha and two beta chains).
Each subunit contains a haem group with iron for oxygen binding.
What is erythropoiesis?
The process of producing red blood cells in the bone marrow.
Stimulated by erythropoietin from the kidneys.
What is the role of platelets in haemostasis?
Aggregate at the site of vascular injury.
Form a platelet plug to prevent bleeding.
Release granules that recruit other platelets and coagulation factors.
What is the function of lymphocytes?
T cells: Cell-mediated immunity.
B cells: Produce antibodies for humoral immunity.
Natural killer cells: Destroy virus-infected and cancerous cells.
What is the difference between innate and adaptive immunity?
Innate: Immediate, non-specific defense (e.g., neutrophils, macrophages).
Adaptive: Specific, delayed response (e.g., T cells, B cells).
What is the role of neutrophils?
First responders to bacterial infections.
Perform phagocytosis to engulf and destroy pathogens.
What causes eosinophilia?
Allergic reactions.
Parasitic infections.
Certain cancers (e.g., Hodgkin lymphoma).
What is thrombocytopenia?
Low platelet count.
Causes include bone marrow failure, increased destruction, or sequestration in the spleen.
What is thrombocytosis?
High platelet count.
May be reactive (due to inflammation) or related to myeloproliferative disorders.
What is the function of basophils?
Release histamine and other mediators during allergic reactions.
What are the primary causes of neutropenia?
Chemotherapy.
Bone marrow suppression.
Severe infections.
What is the function of monocytes?
Phagocytosis of pathogens and debris.
Differentiate into macrophages in tissues.
Present antigens to lymphocytes.